A61B5/022—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers

A61B5/02233—Occluders specially adapted therefor

Abstract

The invention relates to a continuous, non-invasive (bloodless) sphygmomanometer. The apparatus consists of arterial signal receivers (12) which transmit the signal of the arterial flow to a computer (10) that regulates the pressure in a pressure chamber (3) via an inlet valve (3) and an outlet valve (4). Said pressure is fed to the human extremity by means of a pressure pad (7). The artery is located in said extremity. The pressure thus applied matches the intra-arterial blood pressure when the signal of the arterial signal receivers (12) is represented in a certain manner. In another embodiment, the arterial signal receivers (12) are configured as pressure sensors. The mouldable membrane (9) of the pressure pad (7) is separated into two separate areas (24a and 24b) by means of septums (23). The area (24a) is filled with a liquid for better transmitting the arterial signal which is then outputted by a pressure sensor acting as arterial signal receiver (12).

Description

Continuous, non-invasive blood pressure measuring device

In medicine, there is a need of frequent, if possible, continuous blood pressure measurement. For this, new devices have been designed in recent years. An important innovation brought the method of Penaz (Digest of the 10 l International Conference on Medical and Biological Engineering 1973 Dresden), in which a finger is illuminated and is kept constant by a servo control of the registered river.

This photo plethysmographic method was developed by some other seized (Yamakoshi, Wesseling, TNO). EP 537 383 (TNO) April 21, 1993 (21/04/93) shows an inflatable finger cuff for non-invasive continuous Blutdracküberprüf ng. The inflatable cylindrical space is pneumatically connected to a fluid source. An infrared light source and a detector are positioned on both sides of the finger within the fixed cylinder. There is a valve for filling the cylinder is provided with gas. There are electric cables for the infrared light source and detector through felt US 4510940 A (WESSELING) 16 April 1985 (16.04.85), and US 4,539,997 A (WESSELING) 1 O.September 1985 (10.09.85) show a An apparatus for continuous non-invasive measurement of blood pressure. There are provided a fluid-filled cuff, a light source, a light detector and a differential pressure amplifier. The US 4406289 A (WESSELING) 27 September 1983 (27.09.83) also shows such a device according to the prior art.

The documents cited show all only the state of the art, this especially so when one considers that essential to the invention in the main claim are missing.

A major problem of the methods is the one hand in the used cuffs, which must be very accurately placed, on the other hand the employed, very expensive to be manufactured proportional valve are very susceptible to interference and less durable, (US Pat: 4,406,289) and, furthermore, in the calibration of the apparatus which, although can be very precisely indicative of the relative variation in blood pressure, but differs greatly in the absolute measurement of the actual intra-arterial values. Typically, in the previously used proportional valves either a) a tilt rod (flapper) is an electromagnetic shaker is used, which can be moved by an electromagnet alternately in one direction or the other, or b) is used. In both these proportional valves a constant gas flow is given by the pressure chamber, there is always a part of the valve is open. Either the outlet opening to the outside, or inlet port is released from the gas supply. There is no position of the valve in which both inlet and outlet opening are simultaneously closed.

This results in a very high gas demand which, although with a fixed camera little relevance, but is clearly to bear in community-worn devices. A further disadvantage is the use of pressure generating systems (usually pumps and compressors), which must generate a pressure flow without ripple, since this ripple would affect the measuring signal. Pumps and compressors are generate a constant and smooth flow of air in more expensive and generally consume more energy than pressure generating systems that provide a pressure must not fall below a certain threshold. The weight and power consumption of the device is significantly increased.

Another disadvantage of the methods used is that these methods previously used only be used on the finger, but the finger arteries are too small arteries, which are controlled by the body such as the temperature of the finger in the river, so that the pressure in these arteries no longer corresponds to the pressure in the large arteries, the doctors interested in the first place. However, for this reason, do not give the devices previously used (eg Finapres the company Ohmeda) Although very well the relative fluctuations in blood pressure to the absolute values ​​of the pressure, so that the device Finapres was also taken off the market.

Another existing blood pressure measuring device uses the Planartonometrie substantially. In this case, an array of very small Druckaufhehmem which are embedded in silicon is applied to the artery via a Luftdruckbalg, wherein a computer to search out under the pressure sensors that provides the best signal. The pressure in the bladder is not changed after reaching a good signal, the calibration of the pressure curve is via single or multiple measurement of oscillometric blood pressure that can be measured on the same arm intermittent. The application of a hard object, namely the array on the artery is deformed so that the pressure values, the outputs of this device greatly differ same uncontrollably from the intra-arterial values. (Zorn et al, Blood Pressure Monitoring 2: 185, 1997) The accurate analysis of the pressure curves can be used in addition with the aid of an extended Windkessel model in a known manner in order to calculate the compliance of the large and small vessels as demonstrated by the Watt and Burrus has been. Furthermore, for example, can also be the pressure in the central aorta to be constructed with frequency analysis or a so-called augmentation index are calculated, the very well reflects the actual mechanical load of the heart and vascular system. So far, the so-called Aplanationstonometrie was used in a hard Druckaumehmer was brought by hand or by micrometer screw to the artery in order to relieve the arterial wall. This has been brought the disadvantage that the pressure with the Druckaumehmer was on the artery was not known and that it was extremely laborious, manually make the artery exactly.

The subject invention aims at avoiding the aforementioned problems by creating a new blood pressure meter.

The blood pressure measuring device according to the invention is described in more detail in the figures. In Fig. 1, the new blood pressure measuring system is described in detail. In Fig. 2 described the new finger cuff detail. Fig. 3 shows an embodiment of the blood pressure measuring system, wherein Druckaumehmer be used as Arteriensignalaufhehmer. Fig. 4 shows an embodiment of the blood pressure measuring system, wherein a plurality Signalaufhehmer be used as Arteriensignalaufhehmer. Fig. 5, 6 and 7 show detailed views of the Arteriensignalaufhehmer.

In Fig. 1, the source of gas is marked with 1 in which there could be an air pump or a gas cartridge. 2 with an attenuator, such as a gas filter is located, the high-frequency irregularities of the gas supply, for example, would balance as a gas source using a membrane pump and at the same time serves as a dust filter. 3, the pressure chamber in which the connection is brought to the gas source 1 through an inlet valve. 4 5 with the exhaust valve is characterized. The valves could be conventional proportional valves, but is especially advantageous to use valves with very short switching times, as they are given for example by piezoelectric elements. With switching times of these piezoelectric valves of around one millisecond pressure changes can be achieved, which can be in a frequency range up to 50 Hz here. In the Verwendimg of piezoelectric valves, a digital control of the valves by a computer 10 is particularly easy to achieve, so that the valves characteristics can be played through the digital control, the (conventional proportional valves or when the forced coupling of exhaust and intake valve as for example, in US Pat.Nr .: 4,406,289 Wesseling not realized), or is difficult to achieve. Thus, in the pressure chamber 3, any desired pressure characteristic with an upper cut-off frequency of about 50 Hz, the gas consumption can be set and also be kept low. The pressure chamber may be connected to the pressure chamber 3 via a further change-over valve 6, for example with two or more pressure pads 7 via the lines 3a and 3b of the pressure chamber 3 serving the arterial compression. If only one pressure pad is used, the switching valve 6 can be omitted. 8, the relatively rigid outer wall is in this serves to keep low compliance of the pressure pad. 7 9 with a deformable membrane is in serves the artery compression. In the specific case, the cushions 7 are annular in cross-section, because they are intended for use on the fingers, through which the cushions 7 are attached. 11 with a rigid positioning member is characterized by means of which the two pressure pads may be connected. 7 This has the advantage that the position of the Druckpölster 7 is ensured on the fingers in relatively constant alignment. Characterized a constant position of the attached to the limitation of the Druckpölster 7 Arteriensignalaufhehmer 12 is ensured relative to the underlying the deformable membrane 9 artery. In the Arteriensignalaufhehmern 12 could be, for example light sources and Lichtaufhehmer (arteries signal receiver 12a and arterial signal transmitters 12b) act to measure the flow of the artery, or even for example to Ultraschallaufhehmer or laser or even to Druckaumehmer. Thus, controlled by the Arteriensignalaufhehmer 12, which are also connected to the computer 10, the desired pressure can be produced at any time in the pressure pad. 7 Instead of the shown here Druckpölster 7, marked annular here, of course, any other form, the body portion adapted used could be used. If the blood pressure monitor, for example, be used on the skull above the artery Temporal, is flat Druckpölster 7 would be suitable.

Furthermore, it is somewhere in the range of the communicating cavity formed from the pressure chamber 3 and pressure pad 7, a Druckaumehmer 13 is attached, which measures the pressure in the pressure chamber and passes to the computer 10th As is known, the measured in the pressure chamber with suitable control by the A-rteriensignalaufhehmer 12 corresponds so the arterial pressure. Advantage, it might be in the shown Druckaumehmer 13 a Differenzdruckaufhehmer. This would have the advantage that the pressure measurement can be corrected relative to the heart at all times to the height difference of artery. For this purpose a fluid-filled line would have to be present (indicated schematically in Figure 1 with a heart) to at heart level ranges. Advantageously enough, the fluid-filled line is filled with a liquid 14, which corresponds to the density of blood. The liquid with which the pipe 14 is filled should have a low Ausgasungsgrad. (Such as oily liquids). The hose may, for example, by means of a fixing device 14a (for example, Velcro tape, snap button, clamp, etc.) at the extremity (for example, upper arm or garment) are mounted at heart level. At the heart near end of the line 14 a free-floating membrane could be mounted 14b which can not flow out the liquid, but allows movement of the liquid column. On the free-floating membrane 14b further luftdurchläßige but strapazfähige membrane 14c or a fine-mesh grid 14c could be attached to prevent a violation of the free-floating membrane 14b.

Furthermore, an additional pressure pad 15 may be present, which is best to be above a different artery, over a large artery, which may be connected to another gas source 16 to, for example oscillometric or auscultatory to measure there in a conventional manner the blood pressure , Similarly, the gas source could be used one course with sufficient capacity, but more valves (not shown) would make necessary. It is known that conventional blood pressure measurements as auscultatory measurement or oszilllometrische operate intermittently, that is usually in the minimum distance of one-half to 1 minute. The further pressure pad is also connected to the computer 10 so as to automatically calculate and display the continuous arterial pressure, as determined in the small artery by the pressure pad 7, to the true value of the blood pressure in the great artery, as illustrated by the pressure pad 15 is measured, to be corrected.

The second pressure measurement over a large artery by the pressure pad 15 has yet another advantage: As is known, should the pressure in the pressure pad 7 can be tracked to the mean arterial pressure for the continuous pressure measurement by the pressure pad 7 continuously, that is, the operating point must be readjusted. To readjust the operating point of the continuous blood pressure measurement must be interrupted briefly by pressure pad 7 mostly. Due to the pressure measurement in a different artery by the pressure pad 15 discontinuously large changes in mean arterial pressure can be detected well, and adjusted continuously so automatically and without interruption of the continuous pressure measurement by the pressure pad 7 of the operating point. So a continuous, uninterrupted recording of the true intra-arterial pressure curve is now possible with the described blood pressure measuring device. The automatic changeover from one pressure pad 7 to the other pressure pad 7a through the switching valve 6, a further measure is set such that the pressure measurement is not interrupted, as a possible pain burden on the patient is prevented by the current measurement at the same location. Fig. 2 shows an advantageous embodiment of the pressure pad 7, which consists of a relatively rigid outer wall 8, which are the favorable low compliance on the one hand the pressure pad 7, on the other hand rigid connection allows 11 to the adjacent pressure pad 7a which is similarly constructed. Within the relatively rigid outer wall 8 there is the deformable membrane 9, which lie in the illustrated case, the Arteriensignalaufhehmer 12th Thus there is no interference between the membrane Arteriensignalaufhehmer (Flußaufhehmern) 12 and the arteries 17, which could interfere with the measurement of blood flow. As said, it could be combined with light detectors at the Flußaufhehmern to LED's, (for example photodiodes) laser (or laser diodes) and photodiodes or ultrasonic transducers and - receivers act (arteries signal receiver 12a and arterial signals transmitters 12b). Likewise, the use of additional pressure sensors (see Fig. 3) is possible. For the Arteriensignalaufhehmer 12 recesses 18 are arranged advantageously enough, the relatively rigid outer wall, in which the Arteriensignalaufhehmer may disappear 12 when the deformable membrane 9 closely abuts the rigid outer wall. 8 This narrow concern therefore makes sense to keep the compliance of pressure pad 7 possible low. In the illustrated case, the two Arteriensignalaufhehmer 12a and 12b each mounted at an angle of 120 degrees in order to ensure an optimum signal, the arteries 17 lie Although overlooked the finger bone 19 in the fingers 20, which corresponds to an angle of 180 degrees in the illustrated pressure pad 7, the best signal is obtained, as said at a location of the arterial signal receivers 12a and transmitters 12b arteries signals of approximately 120 degrees to each other, because at the same time an even better and more homogenous pressure on the artery can be exerted. This is however the case, because only then the deformable membrane 9, but not the Arteriensignalaufhehmer come to lie 12a and 12b on the artery 17 which are not deformable.

In the illustrated case, the deformable membrane 9 is composed of a gas-tight and liquid-tight plastic. In order to make the measurement for the patient being participants, is additionally provided between deformable membrane 9 and the body attached to a skin-friendly fabric 21, there may be a, for example, of nylon or other synthetic fabrics, cotton or the like. The skin-friendly tissue can be freely the Arteriensignalaufhehmer 12a and 12b, so that the signal is not impaired. Particularly advantageous are substances that clean easily and disinfected. Furthermore an electrical shield 22 is provided which keeps the electrical noise from the Arteriensignalaufhehmer 12th In the illustrated case, the electrical shield 22 is externally mounted on the rigid outer wall 8, they could also be within the rigid

Outer wall 8 come to rest.

In order also to ensure a proper positioning of the Arteriensignalaufhehmer 12 over the artery 17, if only one pressure pad 7 is present, it may be beneficial also to mount the rigid positioning member 11 to the rigid outer wall 8, if only one pressure cushion is used. The rigid positioning member 11 is then the adjacent body structures (for example, the neighboring fingers, back of the hand, palm in finger, in the case of the thumb the Tenar, not shown) post-formed, and could thus also continue or maintain the ring mold form parts of a ring.

As shown in Fig. 3, it may be convenient to store Druckaumehmer as Arteriensignalaufhehmer 12 in the rigid outer wall 8. In this illustrated case, it may be beneficial, the communicating system which consists of the pressure chamber 3 and pressure pad 7, to divide by additional easily deformable septum 23, creating in the pressure chamber separate regions 24a and 24b. The area 24a located in the region of the Arteriensignalaufhehmers could then with another medium, namely, be filled with fluid to better pass through the transmission of the radiated signals from the artery to Arteriensignalaufhehmer. 25 while a filling or Entlüftungsöffhung is shown, which can be closed and which is located in the relatively rigid outer wall 8, through which the sector 24a can be filled with a liquid. This embodiment has the advantage that the Arteriensignalaufhehmer 12 in the specific case, for example, can also be a high-resolution Druckaufhehmer which can receive the undistorted not attenuated signals from the bone engaging 26 artery 17, without affecting this mechanically. Thus, the continuous pulse curve can be recorded continuously with high resolution, while an accurately known pressure of the artery 17 may be applied over the flexible septa 23rd Thus, the arterial wall can be relaxed, and a genuine pulse curve are continuously registered.

When we use here embodiment, one hand to the Druckaufhehmer 13 which is in communication with the sector 24b of the pressure pad 7 can be measured in a known manner oscillometric blood pressure, and then with knowledge of the systolic, diastolic and mean arterial pressure at any desired pressure in relation thus produced in the liquid-filled portion 24a for systolic, diastolic and mean arterial pressure in the pressure pad 7 and the recording pulse waveform so as to at precisely defined pressure conditions, thereby allowing a bloodless continuous blood pressure recording. Equally, other naturally Arteriensignalaufhehmer can 12 (receivers 12a and transmitters 12b), such as light-sensitive

Sensor and LEDs to be mounted in the rigid outer wall.

As shown in Fig. 4, a plurality of Arteriensignalaufhehmer (12a-d) may be present, wherein a multiplexing circuit 27 and the computer 10 used, the selection of the optimal placed Arteriensignalaufhehmers 12a-d carries out in order to obtain an optimum signal arteries. This is especially convenient to nevertheless allow interference-free signal recording at a variable position of the artery from individual to individual. Ideally it would place the location of the pressure pad 7 via a small artery, such as the digital artery, with the need for recalibration of the measurement via a further pressure pad 15, which is above a large artery to use from the outset only one pressure pad 7 through a large artery which allows continuous pressure measurement, while the absolute values ​​are determined correctly. Thus, an artery is as the Arterias radialis or temporalis, on the one hand large enough to still be representative of the large arteries, on the other hand, however, a arteries signal recording, for example, a flow measurement (through a through radiation or reflection from the underlying bone 26, for example, radius or skull bone) emitted through the arterial signal transmitter 12b waves allowed. The radial artery, for example, also has the added advantage that the artery 17a is in the example yet another artery, namely other artery ulnar present. For the measurement, only the artery must be compressed 17 by the pressure pad 7, but not other artery 17a and thus blood flow is not interrupted in the extremity. For this purpose, only the deformable diaphragm 9 must be inflatable associated with a sector 28 of the rigid outer wall 8 in the area overlying the examined artery 17 while the other artery is not compressed by the deformable membrane 9 17a.

Fig. 5 shows a practical embodiment of the device, as it is of advantage are superposed when the Arteriensignalaufhehmer (receivers 12a and transmitters 12b) of the deformable membrane 9. In this case, the deformable membrane, for example, could be made of latex, not interrupted, but the Arteriensignalaufhehmer 12 is in a deformable lens 29, preferably molded from the same material as the deformable membrane 9 attached to the diaphragm 9 glued (for example, or vulcanized) is. The electrical leads 30 are guided between the deformable membrane 9 and the skin-friendly tissue 21 so that these leads can also be protected mechanically and isolated out to the computer 10th Fig. 6 shows a further embodiment of the proposed apparatus in which the

are attached Arteriensignalaufhehmer 12 on a strip 31, the strip 31 a

represents part of the septum 23, the gas-filled region 24b of the liquid-filled

Section 24a separates. On the side facing away from the side of the body is the gas-filled area

pulled through 24b, so that when increasing the pressure in the pressure chamber 3 (and thus in the gas-filled portion 24a) the Arteriensignalaufhehmer 17 little or no change their position to the artery and in any case not be withdrawn from the body. Characterized always an optimum signal which is independent of the pressure in the pressure chamber 3

achieved Arteriensignalaufhehmer 12th Thus, the Arteriensignalaufhehmer can tilt 12 in the bar 31 does not, for example, may additionally comprise one, preferably two uprights 32 may be fixedly connected to the bar 31 which is movable in the relatively rigid outer wall 8 in guide openings

are mounted 33rd For optimum pressure transmission is possible without loss of pressure from the area 24b to the area 24a, the strip 31 is narrow, so that the septum 23 from the pressure

Area 24b can transmit multiple pages on the area 24a.

As shown in Fig. 7, the uprights 32, guided past outside the gas-filled portion 24b of the pressure pad 7 so that the pressure Poster 7 must not be interrupted.

Claims

1. blood pressure measuring device for the continuous measurement of blood pressure comprising a pressure chamber 3, a gas source 1 to fill this vacuum chamber 1, a pressure pad 7 with Arteriensignalaufhehmern 12 (receivers 12a and transmitters 12b) for determining the flow, one-off in the pressure chamber 3 Druckaufhehmer 13 and a calculator 10, characterized in that the pressure chamber 3 is provided with a respective separate inlet and outlet valves.

2. sphygmomanometer for continuous blood pressure measurement according to claim 1 characterized in that the arterial signal receivers 12a and transmitters are incorporated in the deformable membrane 9 of the pressure pad 7 12b and that a relatively rigid outer wall 8 of the pressure pad is provided in the recesses 18 for the Arteriensignalaufhehmer 12 are available.

3. sphygmomanometer for continuous measurement of blood pressure comprising a pressure chamber 3, a gas source 1 to fill this vacuum chamber 1, a pressure pad 7 with Arteriensignalaufhehmern 12 (receivers 12a and transmitters 12b) for determining the flow, one-off in the pressure chamber 3 Druckaufhehmer 13 and a computer 10 characterized in that the Arteriensignalaufhehmer are incorporated in the faces away from the body side of the pressure pad 7 12 and that in the region of the pressure chamber 3 or pressure pad 7, at least one deformable septum 23 is present and that separate portions 24a and 24b in the in-pressure chamber 3 and are existing pressure pad 7, communicating cavity provided which, for example, are filled with gas or liquid with different media.

4. sphygmomanometer according to claim 3, characterized in that the Arteriensignalaufhehmer are incorporated in, the body side of the septum averted 23 12

5. sphygmomanometer according to claim 4, characterized in that is available for the Arteriensignalaufhehmer 12 and 12a is a bar 31st

6. sphygmomanometer according to claim 5, characterized in that the strip is mounted movably opposite the relatively rigid outer wall 8 31st

7. sphygmomanometer according to claim 6, characterized in that the bar 31 is movably coupled by uprights 32 with the relatively rigid outer wall. 8

8. sphygmomanometer according to claim 1-7, characterized in that the pressure pad 7 is annular.

9. sphygmomanometer according to claim 1-8, characterized in that the rigid outer skin comprising at least one rigid positioning part. 11

10. sphygmomanometer according to claim 9, characterized in that the positioning member forms a ring or parts of a ring.

11. sphygmomanometer according to claim 1-10, characterized in that a further pressure pad 7 is in the other ring, and that the pressure chamber 3 is equipped with a change-over valve 6, thus measured alternately on one and then on the other enclosed by the respective ring part of the body can.

12. sphygmomanometer according to claim 1-11, characterized in that a further pressure pad is at a different artery 15 available for conventional, intermittent, oscillatory or auscultatory blood pressure measurement, and that the operating point for continuous blood pressure measurement by the further pressure pad 15 is regulated.

13. sphygmomanometer according to claim 1-12, characterized in that the computer 10 continuously standardizes the continually measured blood pressure on the measured by the pressure pad 15 intermittent blood pressure.

14. sphygmomanometer according to claim 1-13, characterized in that a plurality of Arteriensignalaufhehmer 12 are present, from which the computer or to the Arteriensignalaufhehmer 12 searches out with the best signal characteristic and controls.

15. sphygmomanometer according to claim 1-14, characterized in that only one sector 26, the relatively rigid outer skin 8, which includes the Arteriensignalaufhehmer 12, is lined with a deformable membrane. 9

16. sphygmomanometer according to claim 1, 2, 8-15, characterized in that the Arteriensignalaufhehmer are attached to each other at an angle of about 120 degrees 12a and 12b.

17 '. Sphygmomanometer according to claim 1-16, characterized in that the Druckaufhehmer 13 is a Differentialdruckaufhehmer 13, one part of which communicates with the interior of the pressure chamber 3 or the pressure pad 7 and the other part is in communication with a fluid-filled line fourteenth

18. sphygmomanometer according to claim 17, characterized in that the fluid-filled line 14 is filled with a poorly-evaporable fluid with a density similar to the blood.

19: sphygmomanometer according to claim 17 and 18, characterized in that the liquid-filled pipe 14 is closed at its side facing away, the Differentialdruckaufhehmer 13 side with a slightly floating membrane 14b.

20. sphygmomanometer according to claim 17-19, characterized in that the easily deformable membrane 14a is surrounded on its outer side with a strain-proof, but air-permeable membrane 14b.

21. sphygmomanometer according to claim 17-20, characterized in that the liquid-filled hose is provided at its end close to the heart with a fixing device 14a.

22 sphygmomanometer according to claim 1-21, characterized in that a gas cartridge is used as a gas source. 1

23 sphygmomanometer according to claim 1, 2, 8-22, characterized in that the Arteriensignalaufhehmer are embedded in a deformable lens 27 12, and that the electrical leads are routed 28 to the Arteriensignalaufhehmern 12 outside the pressure pad 7 and inside the skin-friendly tissue 21st